‘If you’re of a certain age and you meet someone who you are about to go to bed with, and that person doesn’t have a Facebook page, you may be getting a false name. It could be some kind of red flag,’ he says.

Manjoo points out that these judgements don’t apply to older people who were already productive adults before social media became widespread.

The tech news site Slashdotsummed up Der Taggspiegel’s story about social networking as ‘not having a Facebook account could be the first sign that you are a mass murderer.’

It points out that Holmes, who is accused of killing 12 people and an unborn child and wounding 58 others at a movie theater in Aurora, Colorado, and Breivik, who murdered 77 people with a car bomb and mass shooting, did not use Facebook and had small online footprints.

Breivik used MySpace and Holmes was reportedly on the hookup site Adult Friend Finder.

Psychologist Christopher Moeller told the magazine that using Facebook has become a sign of having a healthy social network.

Psychologists have noted that Holmes, along with several noted mass murderers, have lacked any real friends.

And this is what the argument boils down to: It’s the suspicion that not being on Facebook, which has become so normal among young adults, is a sign that you’re abnormal and dysfunctional, or even dangerous, ways.